Sulphatoxymelatonin excretion in older people: relationship to plasma melatonin and renal function.
In order to validate measurement of urinary sulphatoxymelatonin as an accurate method of estimating plasma melatonin secretion in older people, we compared 24 h plasma melatonin secretion and sulphatoxymelatonin excretion with renal function in 20 subjects 62-89 years of age. There was a good correlation between plasma and urinary sulphatoxymelatonin over the same 24 h period (R2 = 0.797) and no relationship between creatinine clearance and sulphatoxymelatonin excretion (R2 = 0.075). The results suggest that sulphatoxymelatonin excretion estimation is a good surrogate measurement of plasma melatonin secretion in older people, at least across the range of creatinine clearance for the subjects in the study, 0.41-1.81 ml/sec.
Baskett
J J
JJ
University Geriatric Unit, North Shore Hospital, Auckland, New Zealand.
Cockrem
J F
JF
Antunovich
T A
TA
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007668:Kidney / Q000502:physiology*; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000097:blood* / Q000652:urine; D008875:Middle Aged; D010870:Pineal Gland / Q000378:metabolism
C054513:6-sulfatoxymelatonin; D003404:Creatinine; D008550:Melatonin